/Engine/Plugins/Enterprise/DatasmithImporter/Source/DatasmithImporter/Public/DatasmithImporterHelper.h
Start the import process for the given factory type. The importer helper will pop up a file dialog to pick the file to import. Next, it will prompt for the folder where the imported assets will be saved. The Datasmith import options then appears and finally the factory import starts.
template<class TFactory> static void Import()